1. Field of the Invention
The present invention relates to a cartridge envelope for removably accommodating a disc cartridge.
2. Description of the Prior Art
As is well known to those skilled in the art, some types of optical discs such as, for example, magnetooptical discs are operatively accommodated within a disc cartridge of a generally rectangular flattened configuration. Not only to protect the disc cartridge from dusts, but also to provide the disc cartridge with an aesthetically appealing feature in the market, the disc cartridge containing the respective optical disc is placed on the market in the form as accommodated within a protective or storage envelope. This type of cartridge envelope for a standardized size of the disc cartridge is known from, for example, the Japanese Laid-open Patent Publication No. 10-175691, published Jun. 30, 1998 and assigned to the assignee of the present invention.
According to the above mentioned publication, the cartridge envelope is generally made up of four separate component parts including a generally rectangular flat casing, a pivotally supported panel and a pair of lock elements. The casing includes top and bottom envelope panels each having left and right side walls and a rear wall. While the rear wall of the top envelope panel is segmented into two, the top envelope panel is mounted on the bottom envelope panel for sliding motion in a direction parallel to the bottom envelope panel and conforming to the direction of insertion of the disc cartridge into the cartridge envelope and also for pivotal motion between closed and opened positions relative to the bottom envelope panel. The top envelope panel when in the closed position overlays the bottom envelope panel to define a cartridge chamber therebetween with the side walls of the top envelope panel positioned inwardly of the adjacent side walls of the bottom envelope panel.
A cartridge retaining member, which in the above mentioned publication is termed a xe2x80x9clock bodyxe2x80x9d and which is a member separate from any one of the top and bottom envelope panels, is mounted on each of the segmented rear wall portions in a snap-fitted fashion. The cartridge retaining member includes a base body and an elongated elastic element having its opposite ends integral with the base body, a generally intermediate portion of which extends outwardly from the base body to depict a generally C-shaped configuration to thereby define an elastic protrusion. Within this prior art cartridge envelope, the elastic protrusions of the respective cartridge retaining members on the segmented rear wall portions protrude inwardly relative to each other and into the cartridge chamber so that, as the disc cartridge is inserted into the cartridge chamber, the elastic protrusions can be inwardly deformed in sliding contact with the respective side walls of the disc cartridge and finally snapped into associated positioning recesses in the disc cartridge that are disposed inside the disc player for engagement therewith to retain the disc cartridge in position inside the disc player. With the elastic protrusions engaged in the associated positioning recesses in the disc cartridge, the latter can be securely retained in position inside the cartridge chamber of the cartridge envelope.
In practice, however, the cartridge retaining members disclosed in the above mentioned publication are not only complicated in shape, but time-consuming and expensive to mount the cartridge retaining members on the segmented wall portions of the top envelope panel which are also complicated in shape and structure. Also, manufacture of the prior art cartridge retaining members requires the use of a complicated and expensive mold assembly. Consequently, the prior art cartridge envelope is expensive to manufacture.
The above mentioned publication also discloses, as prior art to the invention thereof, a cartridge envelope generally similar to that described above, except that the top envelope panel is fixed relative to the bottom envelope panel. Specifically, this cartridge envelope comprises top and bottom envelope halves that are joined together to define the cartridge chamber therein. A cartridge retaining member generally similar in shape to that described above is fixedly mounted on each of opposite side walls of the cartridge envelope and functions in a manner similar to that described. Since this cartridge retaining member is a member separate from any of the top and bottom envelope halves, the use of a complicated mold assembly is necessitated and the cartridge retaining member itself is complicated in shape, resulting in increase of the cost of manufacture of the cartridge envelope as a whole.
Accordingly, the present invention has been devised to substantially eliminate the above discussed problems and disadvantages inherent in the prior art cartridge envelope and is intended to provide an improved cartridge envelope having a capability of securely retaining the disc cartridge once it has been inserted into the cartridge envelope, which envelope can be manufactured in the form of a unitary structure to thereby reduce the cost of manufacture thereof.
Another important object of the present invention is to provide an improved cartridge envelope wherein at least one cartridge retaining member is formed integrally with a wall portion of the envelope structure to thereby simplify the structure of the cartridge envelope.
In order to accomplish these and other objects of the present invention, there is provided a cartridge envelope for removably accommodating a disc cartridge, which includes an envelope structure including top and bottom envelope panels, left and right side walls and a rear wall, all molded together to define a cartridge chamber that opens outwardly in a direction counter to the rear wall through an insertion opening. At least one cartridge retaining member formed in one of the walls forming the envelope structure for removably retaining the disc cartridge securely inside the cartridge chamber once the disc cartridge has been inserted thereinto.
Preferably, the cartridge retaining member is of one-piece structure including a flexible finger and a retaining protuberance formed on the flexible finger so as to protrude inwardly of the cartridge chamber. The retaining protuberance is engageable with an outer surface of the disc cartridge, inserted into the cartridge chamber, to retain the disc cartridge securely inside the cartridge chamber.
One of the positioning recesses disposed generally in the disc cartridge for cooperation with corresponding positioning pins disposed inside the disc player to retain the disc cartridge in position inside the disc player relative to an optical read/write head may be utilized for receiving the retaining protuberance to thereby securely retain the disc cartridge inside the cartridge chamber of the cartridge envelope.
In one preferred embodiment of the present invention, the flexible finger may be supported in a cantilever fashion and the retaining protuberance is formed on a free end of the flexible finger.
In another preferred embodiment of the present invention, the opposite side walls of the envelope structure may have a wall thickness greater than that of the top and bottom panels thereof and each of the opposite side walls may have an inner surface formed with a generally U-sectioned trim groove at a position intermediate of the thickness thereof so as to extend lengthwise of the associated side wall from a front end thereof adjacent the insertion opening to a location spaced a distance inwardly from the rear wall.
In any event, at least one of the opposite side walls of the envelope structure preferably has a portion thereof recessed inwardly to provide a thin-walled portion, and the cartridge retaining member is to be formed in that thin-walled portion with the flexible finger displaceable within the recess so formed in the side wall.